My mathematical approach to punnet square calculations for multiple morph pairings.



We all know that figuring out the odds for any specific outcome in a multi-morph project can be difficult at best. I've devised the following method to calculate the odds:



First off, look at each morph separately. It's much easier to run a punnet square on one morph at a time then combine back later.



Only concern yourself with phenotypic outcomes,



For example, the following, semi complicated, cross:



Sunglow het anery (one hypo gene, two albino genes and one anery gene) mated to:

TH moonglow (one each hypo, albino and anery genes)



Would be divided into three morph calculations:



Hypo = het x het (dominant)

¾ hypo (possible super)

¼ normal



Albino = Homozygous x het (recessive)

½ albino

½ het albino



Anery = het x het (recessive)

¼ anery

¾ pos het anery



For any multi-morph pairing the total number of possible phenotypes is determined by multiplying the individual morph phenotypes. In the example 2x2x2=8



List out the various possible phenotypes:



Hypo(pos super), albino, anery

Hypo(pos super), albino, pos het anery

Hypo(pos super), het albino, anery

Hypo(pos super), het albino, pos het anery

Normal, albino, anery (note: I listed the "normal outcome for the hypo pairing)

Normal, albino, pos het anery

Normal, het albino, anery

Normal, het albino, pos het anery



Then multiply together the individual phenotype fractions:



Hypo(pos super)(¾), albino(½), anery(¼) = ¾ x ½ x ¼ = 3/32

Hypo(pos super), albino, pos het anery = ¾ x ½ x ¾ = 9/32

Hypo(pos super), het albino, anery = ¾ x ½ x ¼ = 3/32

Hypo(pos super), het albino, pos het anery = ¾ x ½ x ¾ = 9/32

Normal, albino, = ¼ x ½ x ¼ = 1/32

Normal, albino, pos het anery = ¼ x ½ x ¾ = 3/32

Normal, het albino, anery = ¼ x ½ x ¼ = 1/32

Normal, het albino, pos het anery = ¼ x ½ x ¾ = 3/32



Clear as mud?
-----
Thanks,





Dave Colling



www.rainbows-r-us-reptiles.com







0.1 Wife (WC and still very fiesty)

0.2 kids (CBB, a big part of our selective breeding program)



LOL, to many snakes to list, last count:

21.29 BRB

19.19 BCI

And those are only the breeders



lots.lots.lots feeder mice and rats

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